Image recording device

ABSTRACT

An image reading device includes a tray unit, a recording unit disposed above the tray unit, an outer guide defining a curved path extending from the tray unit to the recording unit, a sheet feeder configured to feed a sheet from the tray unit to the curved path, and a return guide disposed between the recording unit and the tray unit. The return guide pivots about a shaft and guides the sheet having an image recorded thereon back to the curved path. The tray unit includes at least one supporting portion. The return guide includes at least one supported portion. The at least one supporting portion of the tray unit engages the at least one supported portion of the return guide such that the return guide takes a guiding position in which the return guide defines a return path extending to the curved path.

CROSS REFERENCE TO RELATED APPLICATION

This application is a continuation application of Ser. No. 16/214,954filed Dec. 10, 2018, which is a continuation application of U.S. Ser.No. 15/974,891 filed May 9, 2018, now U.S. Pat. No. 10,207,521 issued onFeb. 19, 2019, which is a continuation application of U.S. Ser. No.15/637,502 filed Jun. 29, 2017, now U.S. Pat. No. 9,975,356 issued onMay 22, 2018 which is a continuation application of U.S. Ser. No.15/405,910 filed on Jan. 13, 2017, now U.S. Pat. No. 9,840,095 issued onDec. 12, 2017 which is a continuation application of U.S. Ser. No.15/062,647 filed on Mar. 7, 2016, now U.S. Pat. No. 9,545,798 issued onJan. 17, 2017 which is a continuation application of U.S. Ser. No.13/960,306 filed on Aug. 6, 2013, now U.S. Pat. No. 9,278,558 issued onMar. 8, 2016 which is a continuation application of U.S. Ser. No.12/892,377 filed on Sep. 28, 2010, now U.S. Pat. No. 8,508,819 issued onAug. 13, 2013 and claims priority from Japanese Patent Application No.2010-018605, filed on Jan. 29, 2010, the entire disclosures of which areincorporated herein by reference.

BACKGROUND OF THE INVENTION 1. Field of the Invention

This application relates to an image reading device configured to recordan image on both sides of a sheet, and particularly to an imagerecording device comprising a return guide configured to convey a sheethaving an image recorded thereon back to a recording unit.

2. Description of Related Art

A known image recording device is configured to record an image on bothsides of a sheet and comprises a sheet tray, a feed roller, and arecording unit disposed above the sheet tray. The feed roller feeds asheet from the sheet tray toward the recording unit via a curved pathextending between the sheet tray and the recording unit. In adouble-sided recording mode, a sheet having an image recorded on oneside thereof is switched back and returned to the sheet tray, and thefeed roller feeds the sheet again toward the recording unit via thecurved path. Because a path for guiding a sheet for recording one sidethereof and a path for guiding a sheet for recording the other sidethereof are shared, the image recording device is made compact.

However, when the feed roller feeds the sheet returned to the sheettray, the feed roller contacts the surface of the sheet on which animage has been recorded. The feed roller may smear the image on thesheet, or a recording agent, such as ink or toner, may adhere to thefeed roller which, in turn, may soil another sheet.

SUMMARY OF THE INVENTION

A need has arisen for an image recording device that overcomes these andother shortcomings of the related art, and is configured to convey asheet having an image recorded thereon to a recording unit without arisk that the image is damaged while the recording device remainscompact.

According to an embodiment of the invention, an image reading devicecomprises a tray unit configured to hold sheets, a recording unitdisposed above the tray unit, an outer guide defining a curved pathextending from the tray unit to the recording unit, a sheet feederconfigured to feed a sheet from the tray unit to the curved path in afirst direction, and a return guide disposed between the recording unitand the tray unit. The return guide is configured to pivot about a shaftextending in a second direction perpendicular to the first direction andto guide the sheet having an image recorded thereon back to the curvedpath. The tray unit comprises at least one supporting portion. Thereturn guide comprises at least one supported portion. The at least onesupporting portion of the tray unit is configured to engage the at leastone supported portion of the return guide such that the return guidetakes a guiding position in which the return guide defines a return pathextending to the curved path.

Other objects, features, and advantages will be apparent to persons ofordinary skill in the art from the following detailed description of theinvention and the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

For a more complete understanding of the invention, the needs satisfiedthereby, and the features and technical advantages thereof, referencenow is made to the following descriptions taken in connection with theaccompanying drawings.

FIG. 1 is a perspective view of an image recording device, e.g., amulti-function device, according to an embodiment of the invention.

FIG. 2 is a schematic vertical cross-sectional side view of a printer ofthe image recording apparatus of FIG. 1.

FIG. 3 is a schematic partial perspective view of a sheet feeder of theprinter.

FIG. 4 is a schematic plan view of a main tray of a tray unit of theprinter.

FIG. 5 is a schematic plan view of the tray unit.

FIG. 6 is a schematic plan view of the tray unit.

FIG. 7A is a schematic plan view of a lower guide of the printer, andFIG. 7B is a schematic cross-sectional view of the lower guide takenalong line VIIB-VIIB in FIG. 7A.

FIGS. 8A-8D are schematic cross-sectional views illustrating movementsof the tray unit and a rear guide plate of the lower guide.

FIG. 9A is a schematic cross-sectional view illustrating the rear guideplate supported by the tray unit with a second tray in a first position,and FIG. 9B is a schematic cross-sectional view illustrating the rearguide plate supported by the tray unit with the second tray in a secondposition.

FIG. 10 is a schematic cross-sectional view of the rear guide plate andthe tray unit taken along line X-X in FIG. 9B.

DETAILED DESCRIPTION OF EMBODIMENTS

Embodiments of the invention and their features and technical advantagesmay be understood by referring to FIGS. 1-5, like numerals being usedfor like corresponding parts in the various drawings.

FIG. 1 is a perspective view showing the external configuration of animage recording device, e.g., a multi-function device 10, according toan embodiment of the present invention. In the following description, anup-down direction 7 will be defined on the basis of a state where themulti-function device 10 is set in a usable position (i.e., the stateshown in FIG. 1), a front-rear direction 8 will be defined with a sideprovided with an opening 13 as being a front side (front face), and aleft-right direction 9 will be defined on the basis of a state where themulti-function device 10 is viewed from the front side (front face).

As shown in FIG. 1, the multi-function device 10 substantially has alow-profile rectangular parallelepiped shape with a width (i.e., thedimension in the left-right direction 9) and a depth (i.e., thedimension in the front-rear direction 8) that are greater than theheight (i.e., the dimension in the up-down direction 7). Mainly, themulti-function device 10 integrally includes an inkjet printer 11provided at a lower section and a scanner 12 provided at an uppersection. The multi-function device 10 has various functions, such as afacsimile function, a printing function, a scanning function, and acopying function. As the printing function, the multi-function device 10has a double-sided recording function for recording images onto bothsides of a recording medium, e.g., a sheet. The functions other than theprinting function are optional. For example, the image recording deviceaccording to the present invention is applicable to a printer that doesnot have a scanning function, a copying function, and a facsimilefunction.

The printer 11 includes a housing 14 having the opening 13 in the frontface thereof. Components of the printer 11 are disposed within thehousing 14. An accommodation space extends continuously from the opening13 toward the interior of the housing 14. A tray unit 78, is fitted inthis accommodation space. The tray unit 78 is configured to be insertedinto and removed from the interior of the housing 14 horizontally in thefront-rear direction 8 through the opening 13. The tray unit 78 includesa first tray, e.g., a main tray 80, configured to hold sheets of varioussizes, and a second tray 81 configured to slide on the main tray 80, inthe front-rear direction 8. A detailed description of the configurationof the tray unit 78 will be provided later.

The printer 11 mainly includes the tray unit 78, the sheet feeder 15that picks up a sheet from the tray unit 78, an inkjet recording unit 24that emits ink droplets onto the sheet fed by the sheet feeder 15 so asto form an image on the sheet, a path switching unit 41, a dischargetray 79 that holds the sheet having undergone recording and dischargedto the outside, and a controller that controls, for example, rotation ofconvey rollers included in the printer 11. These components are providedwithin the housing 14. The recording unit 24 is not limited to theinkjet type and may be of various recording types, such as anelectrophotographic type or a thermal recording type. The discharge tray79 may be integrated with the tray unit 78 or may be fixed to a frame orthe like of the housing 14.

A convey path 65 that extends upward and frontward from a rear end ofthe tray unit 78 to the discharge tray 79 via the recording unit 24 isformed inside the printer 11. The sheet is guided from the tray unit 78to the discharge tray 79 and travels along the convey path. The conveypath 65 is segmented into a curved path 65A formed in a curved shapebetween the rear end of the tray unit 78 and the recording unit 24, anda discharge path 65B formed between the recording unit 24 and thedischarge tray 79.

As shown in FIG. 2, the curved path 65A extends from near an upper endof an inclined separation plate 22 provided in the tray unit 78 to therecording unit 24. The curved path 65A is defined by a rear cover 18provided at the rear of the housing 14 and an inner guide 19 disposedfacing the rear cover 18 with a predetermined distance therebetween. Therear cover 18, which serves as an outer guide, and the inner guide 19are formed in a substantially arc shape centered on the interior of theprinter 11.

The inner face of the rear cover 18 defines the curved path 65A, and theouter face of the rear cover 18 defines the rear face of the housing 14.The rear cover 18 is supported in an openable/closable manner about ashaft 20, provided at a lower portion of the housing 14, between aclosed position (i.e., a position denoted by a solid line in FIG. 2) inwhich the rear cover 18 covers the rear face of the housing 14 and anopen position (i.e., a position denoted by a dashed line in FIG. 2) inwhich the rear cover 18 is moved away from the housing 14 so as toexpose the curved path 65A. When the rear cover 18 is set in the closedposition, the inner surface thereof defines the curved path 65A. Evenwhen the sheet is jammed in the curved path 65A, the jammed sheet can bereadily accessed by simply opening the rear cover 18.

The discharge path 65B is defined by an upper discharge guide 82 and alower discharge guide 83 that are provided to the front of the recordingunit 24.

A branch port 36 is formed at the front side of the lower dischargeguide 83. When performing double-sided recording, the sheet conveyedalong the discharge path 65B is switched back at the downstream side ofthe branch port 36 so as to be conveyed toward a return path 67, to bedescribed later.

The recording unit 24 is disposed above the tray unit 78. The recordingunit 24 is configured to reciprocate along a guide rail (not shown)extending in a direction perpendicular to the drawing sheet plane ofFIG. 2 (i.e., the left-right direction 9 in FIG. 1). A platen 42 isprovided below the recording unit 24. When image recording is performedby the recording unit 24, the platen 42 supports the sheet in ahorizontal state. In the course of a reciprocating process in the mainscanning direction, the recording unit 24 emits ink supplied from an inkcartridge (not shown) as very small ink droplets through nozzles 39toward the sheet conveyed on the platen 42. Consequently, an image isrecorded onto the sheet.

The convey path 65 is provided with a first convey roller 60 and asecond convey roller 62 for nipping and conveying the sheet. Therecording unit 24 is provided between the first convey roller 60 and thesecond convey roller 62. A pinch roller 61 is disposed in pressurecontact with the first convey roller 60, and a spur roller 63 isdisposed in pressure contact with the second convey roller 62. In thisembodiment, the first convey roller 60 and the second convey roller 62are rotated by receiving a rotational driving force from a convey motor(not shown) via a transmission mechanism (not shown). Furthermore, arotational driving force for rotating a third convey roller 45, to bedescribed later, in a forward rotating direction or a reverse rotatingdirection is also transmitted thereto from the convey motor.Alternatively, a driving source for the first convey roller 60 and thesecond convey roller 62 and a driving source for the third convey roller45 may be provided independently of each other.

The sheet feeder is provided between the recording unit 24 and the trayunit 78, more specifically, between a lower guide 90, to be describedlater, and the tray unit 78. The sheet feeder 15 is configured to conveysheets accommodated in the tray unit 78 to the curved path 65A andincludes a feed roller 25, a feed arm 26 formed of an arm-like member,and a transmission mechanism 27.

The feed roller 25 is configured to pick up the sheets held by the trayunit 78 one by one and feed each sheet to the curved path 65A. The feedroller 25 is made of an elastic material, such as silicon or NBR, so asto increase the contact friction against the sheet. Alternatively, thefeed roller 25 may be a plastic roller whose roller surface is coatedwith an elastic material. The feed roller 25 is rotatably supported by afree end of the feed arm 26. The feed roller 25 is rotationally drivenby receiving a rotating force of a feed motor (not shown), serving as adriving source, via the transmission mechanism 27. The transmissionmechanism 27 is supported by the feed arm 26 and includes a plurality ofgears that are arranged substantially linearly in the extendingdirection of the feed arm 26.

A shaft 28 is provided between the recording unit 24 and the tray unit78. The shaft 28 is a rod-like member extending in the left-rightdirection 9 of the housing 14. The feed arm 26 has its base endsupported by a midsection of the shaft 28 and is pivotable about theshaft 28. Therefore, the feed arm 26 is vertically movable into and outof contact with the tray unit 78. The feed arm 26 extends obliquelydownward toward the rear of the housing 14 from the pivotal center ofthe shaft 28. The free end of the feed arm 26 extends to anaccommodation space for the tray unit 78. The feed arm 26 is pivotallybiased in a direction indicated by an arrow 29 in FIG. 2 due to its ownweight and/or an elastic force of an elastic member, such as a spring.The shaft 28 also serves as a shaft for pivotably supporting a rearguide plate 92, to be described later.

As shown in FIG. 3, the feed arm 26 includes a pivot plate 30 thatextends rightward from the feed arm 26 and that is long in theleft-right direction 9. The pivot plate 30 extends rightward to theexterior of the main tray 80. Similar to the feed arm 26, the pivotplate 30 is pivotable about the shaft 28. When the pivot plate 30pivots, the feed arm 26 also pivots in the same direction. An upper end56A of a side plate 56 of the main tray 80 has a guide surface 58 formedas a V-shaped notch. The guide surface 58 is provided at a positioncorresponding to the pivot plate 30 of the feed arm 26. In detail, in astate where the tray unit 78 is fitted in the housing 14, a lower end30A of the pivot plate 30 is positioned at a lowermost part of theV-shaped guide surface 58. At this position, the feed arm 26 can pivotdownward until bringing the feed roller 25 into contact with a baseplate 54. In this embodiment, the pivot plate 30 is guided by the guidesurface 58 during the insertion and removal of the tray unit 78 into orfrom the housing 14, thereby causing the feed arm 26 to pivot.Consequently, the feed roller 25 vertically moves together with the feedarm 26. The upper end 56A has a first supporting portion 56C, to bedescribed later, that is located to the rear of the guide surface 58.The first supporting portion 56C forms a horizontal surface that is sethigher than the guide surface 58. When the pivot plate 30 is supportedby the first supporting portion 56C, the feed arm 26 is supported at apivot position where the feed roller 25 is lifted to a position higherthan the inclined separation plate 22.

Because the feed arm 26 and a support mechanism therefore are formed inthis manner, the feed arm 26 can move up and down relative to the trayunit 78. Furthermore, when the tray unit 78 is being inserted into thehousing 14, the rear end (such as the inclined separation plate 22) ofthe tray unit 78 comes into abutment with the pivot plate 30 so as tocause the feed arm 26 to pivot upward. Consequently, the feed roller 25is lifted upward together with the feed arm 26. Then, when the tray unit78 is positioned below the feed roller 25, the pivot plate 30 is fittedin the V-shaped guide surface 58, causing the feed arm 26 to pivotdownward and the feed roller 25 to descend accordingly. As a result, thefeed roller 25 comes into pressure contact with the upper surface of thesheets held by the tray unit 78. In this case, when the second tray 81is set at a first position (i.e., a position denoted by a solid line inFIG. 2) at the front side, the feed arm 26 takes a position for feedingthe sheets in the main tray 80 to the curved path 65A such that the feedroller 25 comes into contact with the upper surface of the sheets in themain tray 80. A right side plate 85 (see FIG. 6) of the second tray 81has a guide surface 84 formed as a V-shaped notch and having a similarfunction to that of the guide surface 58. Therefore, when the secondtray 81 is set at a second position (i.e., a position denoted by adashed line in FIG. 2) at the rear side, the feed arm 26 takes aposition for feeding the sheets in the second tray 81 to the curved path65A such that the feed roller 25 comes into contact with the uppersurface of the sheets in the second tray 81. On the other hand, when thetray unit 78 is being removed from the housing 14, the feed roller 25 istemporarily lifted upward together with the feed arm 26 by the guidesurface 58 so as not to collide with the inclined separation plate 22.Then, after the feed roller 25 moves over the inclined separation plate22, the feed arm 26 is no longer supported by the tray unit 78, causingthe feed roller 25 to descend together with the feed arm 26 as iffalling from the tray unit 78.

The frame of the housing 14 is provided with a stopper 71 (see FIG. 8D)for preventing the feed roller 25 from coming into contact with thebottom face of the housing 14 even after the tray unit 78 is removedfrom the housing 14. When the tray unit 78 is not fitted in the housing14, the stopper 71 is in abutment with the feed arm 26 and prevents thefeed arm 26 from pivoting downward such that the feed roller 25 does notmove lower than a predetermined position distant from the bottom face ofthe housing 14.

As shown in FIG. 2, the tray unit 78 is provided below the sheet feeder15 and includes the main tray 80 and the second tray 81.

The main tray 80 is configured to accommodate letter-size (216 mm×274mm), legal-size (216 mm×356 mm), and A4-size (210 mm×297 mm) sheets. Inthe multi-function device 10 according to this embodiment, A4-size orB5-size sheets are mainly accommodated in the main tray 80.

As shown in FIG. 4, the main tray 80 includes the base plate 54 on whichthe sheets are placed, side plates 55 and 56 standing upright fromopposite ends of the base plate 54 in the left-right direction 9 andextending in the front-rear direction 8, and the inclined separationplate 22 standing on the rear end of the base plate 54 and extending inthe left-right direction 9. The main tray 80 has a shape of asubstantially rectangular box whose upper surface is open. The inclinedseparation plate 22 is inclined rearward so as to allow for smoothfeeding of the sheets.

As shown in FIG. 3, opposite ends of the main tray 80 in the left-rightdirection 9, which is a widthwise direction of the tray unit 78, includefirst supporting portions 55C and 56C, respectively. The firstsupporting portion 56C is a portion of the upper end 56A of the rightside plate 56 and is located to the rear of the guide surface 58. Thefirst supporting portion 55C is a portion of an upper end 55A of theleft side plate 55 and is located opposite to the first supportingportion 56C in the left-right direction 9. The first supporting portion55C is integrated with the side plate 55. The first supporting portion56C is integrated with the side plate 56. The first supporting portions55C and 56C function together with projections 102, to be describedlater.

As shown in FIG. 5, the side plate 55 includes a plate-like support rail55B that protrudes toward the side plate 56 from the inner surface ofthe side plate 55. Similarly, the side plate 56 includes a plate-likesupport rail 56B that protrudes toward the side plate 55 from the innersurface of the side plate 56. The support rails 55B and 56B extend inthe front-rear direction 8. The second tray 81, to be described later,is supported in a slidable manner in the front-rear direction 8 by thesesupport rails 55B and 56B.

The main tray 80 includes a pair of side guides 75 extending on the baseplate 54 in the front-rear direction 8. The main tray 80 includes aknown mechanism that interlocks the side guides 75. Therefore, forexample, when one of the side guides 75 is slid toward one side(rightward) in the left-right direction 9, the other side guide 75 isdriven in conjunction with this sliding operation so as to be slidtoward the opposite side (leftward). Consequently, if the width of thesheets placed on the base plate 54 is smaller than the distance betweenthe side guides 75, the side guides 75 are slid toward the oppositeedges of the sheets so as to bring the side guides 75 into abutment withthe opposite edges of the sheets. Thus, a center position of the sheetsin the width direction thereof (i.e., the left-right direction 9) can besubstantially aligned with the center of the main tray 80 in the widthdirection thereof. Even when sheets having a size smaller than the widthof the main tray 80 are placed thereon, the sheets are positioned in themiddle of the main tray 80 by the side guides 75. Alternatively, asingle side guide may be provided. In that case, the sheets ispositioned between the side guide and one of the side plates 55 and 56.

Furthermore, a rear guide 77 is supported on the base plate 54 in aslidable manner in the front-rear direction 8. Therefore, by sliding therear guide 77 toward the rear edges of the sheets placed on the maintray 80, the sheets are pushed toward the rear side of the main tray 80.

FIGS. 5 and 6 are plan views schematically showing the configuration ofthe tray unit 78. As shown in FIGS. 5 and 6, the second tray 81 isprovided in the upper portion of the main tray 80. The second tray 81 isa flat rectangular member designed such that the dimension thereof inthe left-right direction 9 is slightly smaller than the dimension of themain tray 80 in the left-right direction 9 and that the dimensionthereof in the front-rear direction 8 is somewhat smaller than thedimension of the main tray 80 in the front-rear direction 8. A sheetholding portion 131 is provided in the middle of the second tray 81 inthe left-right direction 9. This sheet holding portion 131 accommodatesthe sheets. In this embodiment, the sheet holding portion 131 isdesigned so as to have a width that is smaller than that of a sheetholding surface of the main tray 80, and is configured to holdpostcard-size (e.g., with a short side of 90-107 mm×a long side of140-154 mm) sheets at the largest. The sheet holding portion 131 mainlyaccommodates postcard-size or L photo-size (89 mm×127 mm) sheets (suchas postcards and glossy paper).

The sheet holding portion 131 of the second tray 81 includes a pair ofside guides 132 extending in the front-rear direction 8 and a rear guide133 supported in a slidable manner in the front-rear direction 8. Theside guides 132 and the rear guide 133 are substantially similar to theside guides 75 and the rear guide 77 of the main tray 80. However, thepair of side guides 132 include second supporting portions 134,respectively. The second supporting portions 134 are spaced from eachother in the left-right direction 9, which is the widthwise direction ofthe tray unit 78. The second supporting portions 134 are integrated withthe respective side guides 132. The second supporting portions 134 areplate members extending from the upper ends of the respective sideguides 132 toward the middle of the second tray 81 in the widthdirection thereof. The two second supporting portions 134 functionstogether with protrusions 136, to be described later. Alternatively, asingle side guide may be provided. In that case, a side plate may beprovided along one end of the second tray 81 in the left-right direction9 such that the sheets are positioned between this side plate and theside guide.

The second tray 81 is supported by the aforementioned support rails 55Band 56B of the main tray 80. In detail, the opposite ends of the secondtray 81 in the left-right direction 9 are respectively supported by theupper surfaces of the support rails 55B and 56B. The second tray 81 issupported in a movable manner in the main tray 80 so as to slide in thefront-rear direction 8. The second tray 81 is slidable between thesecond position (see FIG. 6) at which a rear end 81A thereof is inabutment with an inner surface 22A of the inclined separation plate 22so that the second tray 81 is adjacent to the curved path 65A, and thefirst position (see FIG. 5) at which the rear end 81A is distant fromthe inclined separation plate 22 toward the front side by apredetermined distance.

The support mechanism for the second tray 81 is not limited to thesupport rails 55B and 56B extending in the front-rear direction 8, asdescribed above, and may be of any kind so long as the support mechanismcan support the second tray 81 in a movable manner in the front-reardirection 8 in the main tray 80.

When the second tray 81 is set in the first position, the rear-sideupper surface of the main tray 80 is open. In this state, the feedroller 25 descends toward the main tray 80 through the opening in therear-side upper surface of the main tray 80 so as to come into contactwith the sheets held by the main tray 80. When the feed roller 25rotates in this state, the sheets held by the main tray 80 are fedone-by-one toward the curved path 65A.

On the other hand, when the second tray 81 is slid from the firstposition to the second position, the rear end 81A of the second tray 81pushes the pivot plate 30 upward during the sliding process. This causesthe feed arm 26 to be pushed upward, whereby the feed roller 25 ispositioned on the second tray 81. When the feed roller 25 is positionedon the second tray 81, the feed roller 25 comes into contact with theupper surface of the sheets held by the second tray 81. When the feedroller 25 rotates in this state, the sheets held by the second tray 81are fed one-by-one toward the curved path 65A.

As shown in FIG. 2, the path switching unit 41 is disposed near thebranch port 36 in the convey path 65. The path switching unit 41includes a third convey roller 45, a spur roller 46, and a flap 49.

The third convey roller 45 is provided at the downstream side of thelower discharge guide 83. The branch port 36 is formed between the thirdconvey roller 45 and the lower discharge guide 83. The third conveyroller 45 is rotatably supported by the frame or the like of the housing14. The spur roller 46 is disposed above the third convey roller 45 andis in pressure contact with a roller surface of the third convey roller45 due to its own weight and/or a spring or the like. The spur roller 46is rotatably supported by a downstream end of the upper discharge guide82. The third convey roller 45 receives a driving force in the forwardrotating direction or the reverse rotating direction from the conveymotor so as to be rotationally driven in the forward rotating directionor the reverse rotating direction. For example, in the single-sidedrecording mode, the third convey roller 45 is rotationally driven in theforward rotating direction. Thus, the sheet is nipped between the thirdconvey roller 45 and the spur roller 46 and is discharged onto thedischarge tray 79 at the front side. On the other hand, in thedouble-sided recording mode, the rotating direction of the third conveyroller 45 is switched from the forward rotating direction to the reverserotating direction while the trailing edge of the sheet is nippedbetween the third convey roller 45 and the spur roller 46.

A shaft 87 extending in the direction perpendicular to the drawing sheetplane of FIG. 2 (i.e., the left-right direction 9) is provided in theframe or the like of the housing 14. The flap 49 extends substantiallydownstream from the shaft 87. The flap 49 is pivotably supported by theshaft 87. The flap 49 supports a spur roller 47 and a spur roller 48that are separated from each other in the extending direction of theflap 49. The flap 49 is positionally changeable and is pivotable betweena discharge position (i.e., a position denoted by a dashed line in FIG.2) in which the flap 49 is positioned higher than the lower dischargeguide 83, and a reverse position (i.e., a position denoted by a solidline in FIG. 2) in which a protruding end 49A of the flap 49 ispositioned lower than the branch port 36. Because such a flap 49 isprovided, when the trailing edge of the sheet passes the flap 49 and theflap 49 is subsequently set in the reverse position, the trailing edgeof the sheet is oriented downward of the branch port 36. When the thirdconvey roller 45 subsequently rotates in the reverse direction, thesheet is switched back toward the return path 67.

The return path 67 is formed inside the printer 11. The return path 67branches off from the branch port 36 of the discharge path 65B andextends rearward through between the recording unit 24 and the sheetfeeder 15 so as to merge with a merge point 37 located at anintermediate position of the curved path 65A. The return path 67 issegmented into an inclined path 67A at the front side, and a horizontalpath 67B at the rear side. The sheet switched back at the path switchingunit 41 travels along the return path 67 back to the curved path 65A.The return path 67 is formed by an upper stationary guide plate 43 fixedto the housing 14 and by the lower guide 90, to be described below.

As shown in FIG. 2, the lower guide 90 is provided between the recordingunit 24 and the tray unit 78, more specifically, above the sheet feeder15. The lower guide 90 includes a front guide plate 91 disposed to thefront of the shaft 28 and a rear guide plate 92 disposed to the rear ofthe shaft 28. The lower guide 90 guides the sheet having an imagerecorded thereon back to the curved path 65A.

FIGS. 7A and 7B schematically illustrate the configuration of the lowerguide 90. FIGS. 7A and 7B illustrate a state where the rear guide plate92 is set in a horizontal position. The front guide plate 91 and therear guide plate 92 are each formed of a flat-plate member having awidth in the left-right direction that is substantially the same as thewidth of the tray unit 78.

As shown in FIG. 2, the front guide plate 91 has an inclined surfacethat is inclined downward and rearward from the branch port 36. A frontportion of the upper stationary guide plate 43 is disposed facing thefront guide plate 91 with a predetermined distance therebetween throughwhich the sheet can pass. The inclined path 67A of the return path 67 isdefined by the front guide plate 91 and the front portion of the upperstationary guide plate 43.

The rear guide plate 92 includes bearings 95 at opposite end portions inthe left-right direction 9 of the front end thereof. The bearings 95 hasshaft holes (not shown) through which the shaft 28 extends. Thus, therear guide plate 92 is pivotable about the shaft 28 while the rear endof the rear guide plate 92 is a free end. Specifically, the rear guideplate 92 and the feed arm 26 are pivotably supported by the same shaft28. As described later, the rear guide plate 92 is configured to pivotrelative to the feed arm 26 in response to the insertion and removal ofthe tray unit 78. Although the rear guide plate 92 and the feed arm 26are pivotably supported by the same shaft 28, a pivot shaft differentfrom the shaft 28 may be provided for pivotably supporting the rearguide plate 92.

The rear guide plate 92 includes on the lower surface thereof a pair ofprojections 102 respectively provided at the opposite ends in theleft-right direction 9, and a pair of protrusions 136 provided in themidsection in the left-right direction 9 and separated from each otherby a predetermined distance in the left-right direction 9. Theprojections 102 and the protrusions 136 are located on a free end sideof the rear guide plate 92.

The projections 102 protrude downward from the lower surface of the rearguide plate 92 and function as supported portions. The projections 102may be integrally formed with the lower surface of the rear guide plate92. When the tray unit 78 is fitted in the housing 14, the projections102 are engaged with the aforementioned first supporting portions 55Cand 56C so as to be supported from below. Specifically, the projections102 and the first supporting portions 55C and 56C are provided atpositions corresponding to each other so as to be engageable with eachother. Thus, as shown in FIG. 2, the rear guide plate 92 is supported bythe main tray 80 so as to be set in a guiding position, whereby thehorizontal path 67B extending from the shaft 28 to the merge point 37 isformed by the rear guide plate 92. In other words, when the tray unit 78is fitted in the housing 14, the lower guide 90 forms the return path 67for guiding the sheet to the curved path 65A. The position of the rearguide plate 92 in this state is a position in which the sheet is guidedto the curved path 65A. Such a position will be referred to as a“guiding position” hereinafter.

The protrusions 136 protrude downward from the lower surface of the rearguide plate 92 and function as supported portions. The protrusions 136may be integrally formed with lower surface of the rear guide plate 92.The protrusions 136 are provided closer to the center in the left-rightdirection 9 than the pair of projections 102. When the tray unit 78 isfitted in the housing 14 and the second tray 81 is set in theaforementioned second position (i.e., the position shown in FIG. 6), theprotrusions 136 are engaged with the aforementioned second supportingportions 134 so as to be supported from below. Specifically, theprotrusions 136 and the second supporting portions 134 are provided atpositions corresponding to each other so as to be engageable with eachother. Thus, as shown in FIG. 2 with a dashed line, when the second tray81 is set in the second position, the rear guide plate 92 is supportedby the second tray 81 so as to be set in the guiding position. Thehorizontal path 67B extending from the shaft 28 to the merge point 37 isformed by the rear guide plate 92. At this time, the rear guide plate 92is also supported by the main tray so as to be set in the guidingposition. As shown in FIG. 7A, the protrusions 136 each have a certainamount of width in the left-right direction 9. This enables the secondsupporting portions 134 to support the protrusions 136 even when theside guides 132 are slid in the left-right direction 9 on the secondtray 81. Therefore, each of the protrusions 136 is given a width thatcorresponds to the slidable width of the corresponding side guide 132.

An inclined portion 97 that is inclined rearward and upward is formed atthe rear end of the rear guide plate 92. The inclined portion 97overlaps the curved path 65A at the merge point 37. Therefore, the sheetconveyed rearward horizontally from the horizontal path 67B becomesoriented upward by the inclined portion 97. Consequently, the sheettraveling from the horizontal path 67B is conveyed smoothly toward thecurved path 65A.

The rear guide plate 92 also includes on the lower surface thereof acleaning pad 70. The cleaning pad 70 is provided in an area where thelower surface of the rear guide plate 92 comes into contact with thefeed roller 25. Specific examples of the cleaning pad 70 include a feltmember, a cork member, nonwoven cloth, and an adhesive resin member. Bythe contact of the cleaning pad of 70 with the roller surface of thefeed roller 25, the cleaning pad 70 removes foreign matter from theroller surface of the feed roller 25.

FIGS. 8A to 8D are schematic cross-sectional views for explaining themovements of the rear guide plate 92. Specifically, FIG. 8A illustratesa state where the tray unit 78 with the second tray 81 set in the firstposition (see FIG. 5) is fitted in the housing 14, FIG. 8B illustrates astate where the rear guide plate 92 is no longer supported by the firstsupporting portions 55C and 56C and is beginning to descend, FIG. 8Cillustrates a state where the rear guide plate 92 is pushed upward bythe feed roller 25, and FIG. 8D illustrates the positions of the rearguide plate 92 and the feed roller 25 when the tray unit 78 has beenremoved from the housing 14.

As shown in FIG. 8A, when the tray unit 78 is fitted in the housing 14,the projections 102 of the rear guide plate 92 are supported by thefirst supporting portions 55C and 56C of the main tray 80. Thus, therear guide plate 92 is set in the guiding position, and the horizontalpath 67B is formed by the rear guide plate 92. At this time, since thesecond tray 81 is set in the first position (see FIG. 5), theprotrusions 136 of the rear guide plate 92 are not supported. In thisstate, the printer 11 is enabled to feed the sheets from the main tray80 of the tray unit 78. As mentioned above, the main tray 80 holdsA4-size or B5-size sheets (commonly known as plain paper) that arethinner and larger than postcards or the like. Even when one of thesesheets is bent by a large extent while being conveyed along the returnpath 67 toward the curved path 65A, the restoring force of the sheet,which is a force thereof that tries to restore its original state, isrelatively small. Therefore, a downward pressing force generated by therestoring force of the sheet and applied on the rear guide plate 92 isrelatively small. Consequently, the rear guide plate 92 is preventedfrom being bent downward by this pressing force.

When the tray unit 78 is pulled out from the state shown in FIG. 8A, theprojections 102 are no longer supported by the first supporting portions55C and 56C, thereby causing the rear guide plate 92 to pivot downward(see FIG. 8B). In the state shown in FIG. 8B, the feed roller 25 islifted upward by the guide plate 30 guided by the guide surface 58. Whenthe roller surface of the feed roller 25 reaches above the upper end ofthe inclined separation plate 22, the roller surface comes into contactwith the cleaning pad 70. At this time, the cleaning pad 70 removesforeign matter in the contact area of the roller surface.

When the tray unit 78 is pulled out further, the feed roller 25 islifted upward to move beyond the inclined separation plate 22, as shownin FIG. 8C. Thus, the rear guide plate 92 once pivoted downward (seeFIG. 8B) pivots upward again (see FIG. 8C).

When the tray unit 78 is pulled out even further and the tray unit 78 ismoved away from the rear guide plate 92, as shown in FIG. 8D, the feedroller 25 moves downward and the rear guide plate 92 pivots downward tofollow the movement of the feed roller 25.

When the tray unit 78 is inserted into the housing 14 in the reversesequence from a state shown in FIG. 8D to a state shown in FIG. 8A, thepivot plate 30 (see FIG. 3) cooperates with the guide surface 58 toprevent the tray unit 78 from colliding with the feed roller 25, theprojections 102, and the protrusions 136.

The state of the rear guide plate 92 supported by the tray unit 78 whenthe second tray 81 is set in the second position (see FIG. 6) will bedescribed with reference to FIGS. 9A, 9B, and 10.

As shown in FIG. 9A, when the tray unit 78 is fitted in the housing 14while the second tray 81 is set in the first position, the protrusions136 of the rear guide plate 92 are not supported, as mentioned above,and only the projections 102 are supported by the first supportingportions 55C and 56C of the main tray 80. When the second tray 81 isslid on the main tray 80 from the first position to the second positionfrom this state, the feed arm 26 is pushed upward by the second tray 81being slid, causing the feed roller 25 to be lifted onto the second tray81 together with the feed arm 26. Then, when the second tray 81 reachesthe second position, the protrusions 136 of the rear guide plate 92 issupported by the second supporting portions 134 of the second tray 81while the guiding position of the rear guide plate 92 is maintained. Atthis time, the rear guide plate 92 is supported at four support pointsthat are separated from each other by predetermined distances in theleft-right direction 9 (see FIG. 10). The protrusions 134 are located inmore inner positions than the projections 102 in the left-rightdirection 9, i.e., the widthwise direction of the tray unit 78. Thesecond supporting portions 134 are located in more inner positions thanthe first supporting portions 55C and 56C in the left-right direction 9.

As mentioned above, the second tray 81 holds postcards or sheets ofglossy paper that are thicker and smaller than A4-size or B5-size plainpaper. When one of these sheets is conveyed along the return path 67toward the curved path 65A, the sheet is bent by a large extent. In thiscase, the restoring force of the sheet, which is a force thereof thattries to restore its original state, is greater than that of theaforementioned plain paper. Therefore, a downward pressing forcegenerated by the restoring force of the sheet and applied on the rearguide plate 92 is also greater. When the rear guide plate 92 is designedto have a reduced thickness in order to reduce the height dimension ofthe multi-function device 10, there is a possibility that the rear guideplate 92 may be bent downward due to the aforementioned pressing force.However, when the sheet is fed from the second tray 81, the rear guideplate 92 is prevented from being bent downward because the rear guideplate 92 is supported at the four support points separated from eachother by predetermined distances in the left-right direction 9 (see FIG.10), and especially because the pressing force is received by the twosupport points that support the midsection of the rear guide plate 92.

With the above-described configuration, the return path 67 defined bythe lower guide 90 guides the sheet having passed the recording unit 24to the curved path 65A. After the tray unit 78 is removed from thehousing 14, the rear guide plate 92 is no longer supported by the trayunit 78, whereby the rear guide plate 92 pivots downward. Consequently,the horizontal path 67B is enlarged. Therefore, even when the sheet isjammed in the return path 67, the jammed sheet is readily accessed andremoved by opening the rear cover 18.

When the second tray 81 is set in the second position (see FIG. 6), theopposite ends of the rear guide plate 92 are supported by the firstsupporting portions 55C and 56C of the main tray 80, and the midsectionof the rear guide plate 92 is supported by the second supportingportions 134 of the second tray 81. Therefore, even when the sheetentering the curved path 65A from the return path 67 is bent by arelatively large extent and the restoring force thereof is applieddownward onto the rear guide plate 92, the rear guide plate 92 isprevented from being bent downward. This prevents sheet conveyancefailure and sheet jams in the return path 67.

Although the projections 102 are provided in the rear guide plate 92 inthe above-described embodiment, projections may be provided on the sideplates 55 and 56 of the tray unit 78 in place of the projections 102.Furthermore, although the rear guide plate 92 is supported at the foursupport points when the second tray 81 is set in the second position inthe above-described embodiment, a two-point support structure may beused. The opposite ends in the left-right direction 9 of the rear guideplate 92 may be unsupported in a floating manner, and only themidsection of the rear guide plate 92 may be supported by the engagementof the protrusions 136 and the second supporting portions 134.

Furthermore, although the above-described embodiment employs a mechanismthat vertically moves the feed arm 26 and the feed roller 25 by usingthe first supporting portion 56C, the guide surface 58, and the pivotplate 30, the present invention is not limited to such a configuration.The present invention is applicable to any kind of configuration havinga mechanism that vertically moves the feed arm 26 and the feed roller 25in conjunction with the insertion and removal of the tray unit 78.

While the invention has been described in connection with embodiments ofthe invention, it will be understood by those skilled in the art thatvariations and modifications of the embodiments described above may bemade without departing from the scope of the invention. Otherembodiments will be apparent to those skilled in the art from aconsideration of the specification or practice of the inventiondisclosed herein. It is intended that the specification and thedescribed examples are considered merely as exemplary of the invention,with the true scope of the invention being defined by the followingclaims.

What is claimed is:
 1. An image recording device comprising: a sheettray configured to support a sheet therein; a shaft extending in anaxial direction; a sheet feeder including: a feed arm pivotable aboutthe shaft located at one end portion of the feed arm; and a feed rollerrotatably supported by the other end portion of the feed arm andconfigured to feed the sheet from the sheet tray; and a plurality ofgears, wherein the shaft is configured to transmit a driving force,through the plurality of gears, to the feed roller; a recording unitconfigured to record an image on the sheet fed by the feed roller; and areturn guide including: a sheet guide surface defining a part of areturn path and configured to guide the sheet having the image recordedthereon along the return path back toward the recording unit; a surfaceopposite to the sheet guide surface; and a support portion supportingthe shaft such that the feed arm is pivotable, about the shaft, relativeto the surface opposite to the sheet guide surface.
 2. The imagerecording device according to claim 1, wherein the shaft extends throughthe one end portion of the feed arm.
 3. The image recording deviceaccording to claim 1, where the support portion has a hole through whichthe shaft extends.
 4. The image recording device according to claim 1,wherein the sheet feeder further includes a pivot plate connected to thefeed arm and pivotable about the shaft, the pivot plate being configuredto pivot to cause the feed arm to pivot about the shaft, thereby movingup and down the feed roller.
 5. The image recording device according toclaim 4, wherein the pivot plate extends integrally from the feed arm inthe axial direction of the shaft.
 6. The image recording deviceaccording to claim 4, wherein the sheet tray is movable from a sheetfeed position at which the feed roller is in contact with the sheet inthe sheet tray, and the sheet tray includes a guide surface, the guidesurface being configured to, when the sheet tray moves from the sheetfeed position, guide and pivot the pivot plate to cause the feed arm topivot about the shaft, thereby moving up the feed roller away from thesheet in the sheet tray.
 7. The image recording device according toclaim 4, further comprising another tray configured to support a sheettherein and movable on the sheet tray between a non-feed position atwhich the feed roller is in contact with the sheet in the sheet tray,and a feed position at which the feed roller is in contact with thesheet in the other tray, wherein the other tray includes a guide surfaceconfigured to, when the other tray moves from the non-feed positiontoward the feed position, guide and pivot the pivot plate to cause thefeed arm to pivot about the shaft, thereby moving up the feed rolleraway from the sheet in the sheet tray toward the sheet in the othertray.
 8. The image recording device according to claim 1, wherein theshaft is located upstream of the feed roller in a direction in which thesheet is fed by the feed roller.